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Biomedical subjects

H W Gray

Publications and source records attributed to H W Gray.

At least 19 recordsLinked to original sources
PubMed2000

Pethidine-augmented white cell scintigraphy in inflammatory bowel disease.

Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) white cell scintigraphy is invaluable for assessing the presence and extent of disease activity in patients with inflammatory bowel disease. Interpretation of images can be compromised by physiological excretion of tracer into the bowel via the biliary tree. This study assesses the effect of intravenous pethidine administered with the labelled white cells in an attempt to reduce the enterohepatic circulation of the tracer. Ninety-one subjects with proven or suspected inflammatory bowel disease were included in this study, all of whom underwent 99mTc-HMPAO white cell scintigraphy. The control group of 50 subjects underwent the standard protocol for this study performed in our department. The other 41 subjects received an intravenous injection of 0.3 mg/kg of pethidine at the same time as re-injection of the labelled white cells. Images were graded using a five-point scale at both 1 and 2.5 h and categorised as positive, negative or non-diagnostic. Each scan was also assessed for the presence of a visible gall-bladder. The pethidine group had significantly fewer non-diagnostic scans than the control group (P=0.003), and significantly (P=0.001) more studies in which the gall-bladder was visualised. It is concluded that the use of pethidine appears to reduce biliary excretion of tracer during 99mTc-HMPAO white cell scintigraphy. This may allow the delayed images, and early images with low-grade tracer uptake in the bowel, to be interpreted with greater confidence and thereby reduce the number of scans classified as non-diagnostic.

Adolescent↗
PubMed1999

A suggested method for sentinel node biopsy in squamous cell carcinoma of the head and neck.

BACKGROUND: Debate continues over the management of the N0 neck in head and neck malignancy. Therefore, the possibility of performing sentinel node biopsy in these patients was investigated to formulate a method for the procedure. METHODS: Patients undergoing prophylactic or therapeutic neck dissections were injected with either Patent Blue V dye alone or with blue dye and 99m-Tc labeled Albures. The latter group underwent preoperative lymphoscintigraphy. During surgery, blue stained lymphatics were followed to blue nodes, and a neoprobe was used to identify radioactive nodes. RESULTS: In 5 of 13 patients receiving blue dye, a blue node was identified, but none contained tumor. Metastases were identified in other neck nodes in 3 of 5. Sentinel nodes were identified in 15 of 16 patients receiving dye, and Albures. Sentinel node biopsy was accurate in 7 of 7 necks containing impalpable metastases when all nodes had been evaluated after dissection. DISCUSSION: Sentinel node biopsy using blue dye and radiocolloid may prove to be a reliable technique in the N0 neck and warrants further investigation.

Biopsy↗
PubMed1998

Pulmonary embolism exclusion: a practical approach to low probability using the PIOPED data. Prospective Investigation of Pulmonary Embolism Diagnosis.

A recent trend among physicians is the categorisation of lung scans as normal [excludes pulmonary embolism (PE)], high probability (confirms PE) and non-diagnostic (no judgement on PE risk). The low probability scan is therefore being eliminated as a functional category. This occasional survey contends that such an approach is misguided. Correction of the original PIOPED data with certain assumptions provides a more reproducible, albeit restricted, low probability scan category which excludes PE in 97% of cases in the low pre-test clinical category. Patients with a low probability scan with risk factors for PE (i.e. medium clinical risk) will require further investigation. More important, the very low probability scan category excludes PE in 98% of patients with low and more than 92% of patients with medium pre-test clinical likelihood. The demise of "low probability" is premature.

Bayes Theorem↗
PubMed1998

The tender neck: thyroiditis or thyroid abscess?

Following apparent subacute thyroiditis, a 16-year-old girl developed a left thyroid abscess thought to be secondary to steroids and haematogenous spread from a pilonidal abscess. The thyroid suppuration became recurrent and required partial thyroidectomy. Further left-sided abscess formation in the neck prompted a barium swallow which revealed the source of infection to be a sinus tract arising from the left piriform fossa. The patent fourth branchial sinus tract was later excised. All patients with a tender thyroid should have ultrasound-guided fine needle aspiration to establish the diagnosis. If suppuration is confirmed, a barium swallow is advised to exclude a sinus tract from the piriform fossa.

Abscess↗
PubMed1998

A preliminary evaluation of diagnostic odds in lung scan reporting.

Reporting of lung scans for pulmonary embolism (PE) using a descriptive probability notation is tried and tested. Subjectivity in interpretation of this jargon can be a problem for internists. Parallel descriptive and numerical probability reporting has been recommended, but the numerical probability scale is less precise than likelihood ratios expressed as odds. We therefore assessed internists' intuitive understanding of lung scan reports in the odds format compared to the descriptive probability notation. A questionnaire was sent to Scotland's 217 internists to assess their intuitive understanding of odds reporting and to compare their management strategies when confronted by lung scan reports in both an odds and a descriptive probability notation. There was a broad understanding of numerical odds. Internists used 'normal' and '100:1 against PE' identically; similarly, 'low probability' and '10:1 against PE'. There was a statistically significant preference for the diagnosis of PE when internists were given the '1:1 evens' report compared with the 'indeterminate' report. There does appear to be a greater awareness of the risk of PE when non-diagnostic lung scans are reported in numerical odds as compared with the descriptive probability format.

Diagnosis, Differential↗
PubMed1997

Gastric emptying in patients with constipation following childbirth and due to idiopathic slow transit.

BACKGROUND: Idiopathic slow transit constipation (ISTC) is considered to be a heterogeneous condition in which patients have varying sites and degrees of delayed gastrointestinal transit. The majority of patients have pancolonic disease, and colectomy with ileocolorectal anastomosis has been the mainstay of surgical treatment. Severe constipation following traumatic childbirth is now being recognized and this subgroup of patients may have delayed transit confined to the rectosigmoid colon. In theory, proximal transit in these patients should be normal. METHODS: Gastric emptying was studied in patients with constipation following childbirth or ISTC and in controls. After an overnight fast, both patients and controls received breakfast, which consisted of cornflakes, sugar and milk. The liquid marker 111In-labelled di-ethylene tri-amine penta-acetic acid (DTPA) was added to the milk. A solid marker, 99mTc-labelled colloid, was impregnated on to paper and sealed with cellulose. The t1/2 for gastric emptying was calculated. RESULTS: Liquid phase emptying was normal in both constipation following childbirth and ISTC. Solid phase emptying was delayed significantly in ISTC compared with that in patients with constipation following childbirth and controls. In addition, half the patients with ISTC had delayed transit through the small bowel and proximal colon. Small bowel and colonic transit were normal in patients with constipation following childbirth. CONCLUSION: Patients with constipation following childbirth represent a distinct subgroup with normal proximal gastrointestinal function. Gastric emptying studies may be helpful in selecting patients for surgical management of severe constipation.

Adult↗
PubMed1996

Gallbladder visualization in 99Tcm-HMPAO autologous white cell scintigraphy.

The appearance of the gallbladder in images of patients undergoing 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) autologous white cell scans (AWCSs) was compared before and after the introduction of fasting in the white cell scan protocol in our department. Before February 1995, when fasting was not required as a condition of the test, gallbladders were identified in 10 and 13% of 128 patients at 1 and 3 h, respectively. After February 1995, when fasting was imposed for the duration of the AWCS procedure, gallbladders were identified in 44 and 58% of 139 patients undergoing an AWCS at 1 and 3 h, respectively (P < 0.01). While further studies are required to show that fasting affects the false-positive rate, the results suggest that the degradation products of 99Tcm-HMPAO may be retained in the biliary system longer during fasting. Fasting should therefore be included in the protocol for an AWCS, particularly in the evaluation of inflammatory bowel disease (IBD) when 99Tcm-HMPAO is the cell label used.

Eating↗
PubMed1995

Indium-111 leucocyte scintigraphy and ultrasound scanning in the detection of intra-abdominal abscesses in patients without localizing signs.

The clinical records of 45 patients with suspected intra-abdominal sepsis but without localizing abdominal signs were retrospectively reviewed. All had undergone both indium-111 leucocyte scintigraphy and real time ultrasound. Twenty-two of the 45 patients were subsequently shown to have intra-abdominal abscesses. Twenty-one patients were identified correctly by indium-111 scintigraphy (sensitivity 95%) and 10 by ultrasound (US: sensitivity 45%). There were two false positive scintiscans (specificity 91%) but no false positive US scans (specificity 100%). There was no correlation between the peripheral white cell count and the presence of absence of an abscess or the likelihood of obtaining a positive scintiscan result. Because of the excellent specificity ultrasound scanning should remain the initial investigations in this group of critically ill patients with indium-111 scintigraphy being used to clarify the US findings or in US negative patients.

Abdominal Abscess↗
PubMed1993

Radionuclide migration through the genital tract in infertile women with endometriosis.

The migration of radionuclide through the genital tract was observed, comparing 20 patients with endometriosis and infertility with a control group of 23 infertile patients who had a normal pelvis. All patients had patent tubes at laparoscopy and chromopertubation, performed in both groups for the investigation of infertility and to diagnose the presence and extent of endometriosis. A radionuclide tubal test, using human albumin microspheres labelled with 99m-technetium (99mTc) was subsequently undertaken to observe the extent of genital tract migration of radionuclide to uterus, Fallopian tube and peritoneal cavity. The results show that radionuclide migration to the peritoneal cavity was impaired in patients with endometriosis, compared with the control group (30 versus 83%, respectively; P < 0.001). There was no relationship between migration and the severity of endometriosis. We conclude that impaired tubal function may be a cause of infertility in some patients with endometriosis.

Adult↗
PubMed1993

Lung scan reports: interpretation by clinicians.

A questionnaire was sent to 217 consultant physicians in Scotland who were likely to encounter pulmonary embolism (PE) in their daily practice. Replies were received from 194 (89%). Only 34% of physicians understood that a normal lung scan made PE highly unlikely, while 65% considered a low probability scan equivalent to an uncertain diagnosis. This pattern of interpretation of lung scan reports was confirmed by a question on post-test management. After a normal lung scan report, 31% of physicians were uncertain about the diagnosis and this uncertainty increased to 37% for a low probability scan report. This survey has shown misunderstanding by a significant number of physicians of the risk of PE indicated by normal and low probability lung scan reports. It underlines the need for individuals reporting the test to provide informed guidance for clinical staff following ventilation/perfusion (V/Q) imaging. It may point in addition to a need for a more easily understood style of reporting of lung scans.

Humans↗
PubMed1993

Lung scan reporting language: what does it mean?

The aim of this study was to analyse the understanding of the verbal probability language used for communicating lung scan findings. A questionnaire providing a series of expressions of probability in lung scan reporting was sent to 211 consultant nuclear medicine providers in the UK. Respondents were asked to estimate the probability of pulmonary embolism (PE) communicated by each reporting expression on a visual linear probability scale. Analysis of 135 replies revealed a wide variation in the interpretation of the probability language. We suggest that different training, the nature of the probability scale itself and the difficulties of expressing a verbal report on a numerical scale are major reasons for this finding. We conclude that use of verbal probability language complicates the communication of PE risk and that likelihood ratios provide a logical alternative.

Communication↗
PubMed1992

Vertebral metastases and an equivocal bone scan: value of magnetic resonance imaging.

To assess the value of magnetic resonance imaging (MRI) in the investigation of patients with suspected but nonproven vertebral metastases 45 consecutive patients referred in a 6 month period with known primary malignancy and back pain in whom an isotope bone scan was reported as equivocal were studied. All patients had abnormal isotope uptake localized to the spine. Twelve patients were shown to have bony metastases on plain X-ray. In the remainder, where X-rays showed normal or benign appearance, MRI of the spine was offered. Twenty-four patients underwent MRI examination which showed vertebral metastases in 11 cases. Magnetic resonance imaging is shown to be a useful, noninvasive, complementary investigation for evaluation of patients known to have malignant disease and suspected of having vertebral metastases on bone scintigraphy.

Back Pain↗
PubMed1991

Investigation of tubal infertility by radionuclide migration.

Investigation of the tubal factor in infertility is limited to an assessment of anatomical structure and tubal patency. No test of ascendant tubal function is currently available. The migration of radionuclide (99mTc-labelled human albumin microspheres) through the genital tract in 96 infertile women was compared with pelvic findings at laparoscopy and chromopertubation. The radionuclide test correlated with laparoscopy in the diagnosis of patency or blockage in 83 cases (86%). In nine patients, where 'blockage' was diagnosed on the radionuclide test but patency found at laparoscopy, a higher prevalence of pelvic abnormality was found, compared to the 78 patients where both tests demonstrated patency (P less than 0.02). The radionuclide test may facilitate detection of diseased but patent tubes and, as an adjunct to laparoscopy and chromopertubation, may provide useful information about tubal function.

Endometriosis↗